Thursday, October 24, 2013

In order to understand the concept of electronegativity, it is necessary to
take into account the following idea... The molecules are highly dynamic, and
electrons are in constant motion around the atoms, representing the so-called
"electron cloud". The movement of electrons around an atoms is
directly conditioned by its characteristics. That is, if an atom has a greater
ability to take over the electronic cloud, the electrons will be located
predominantly on him. Electronegativity concerns exactly with this capability.
Therefore, the more electronegative an atom is, the greater the portion of the
electron cloud on it. Consequently, the more electronegative atoms tend to have
negative partial charges, because at every moment there will be more electrons
on them than on other atoms .

It is this
asymmetry that is created in the distribution of the electron cloud that causes
the molecules to become polar. Thus, in general , the presence of different
atoms with different electronegativities in a molecule causes the molecule
becomes polar, or at least the region where this happens to become polar .

In the case of
biochemistry , since carbon and hydrogen have similar electronegativities, the
regions of the molecules that contain only these two atoms are nonpolar , while
the presence of oxygen, nitrogen , fluorine , phosphorus , etc., tend to render
that region polar .

Wednesday, October 16, 2013

What do you think about the idea to listen Frank Sinatra singing about biochemistry? Well, it is not the real Frank Sinatra that sings, but Dr. Ahern has adapted the famous song My Way and made another music about the study of biochemistry. It is for sure one of my favourite songs of Dr. Ahern! :)